Chrysomya albiceps (Widemann) develops on animal carcasses and may cause secondary myiases. An adult female Merino sheep presented a lesion of roughly circular shape with a 7.5cm radius in the anterior part of the thorax. A large number of second-instar larvae was removed from the lesion in addition to first-instar larvae from the wool. A third-instar larva was also obtained from the same lesion site and in the laboratory gave origin to a Cochliomyia hominivorax (Coquerel) adult insect. The larvae retrieved from the lesion were natured in laboratory. Pairs consisting of 100 individuals were formed with the adult specimens obtained from the larvae and kept in two cages. In all of the 800 adults reared in the laboratory and examined (100 per generation) the propisternal seta was absent in the spiracle on both sides, this trait was highly stable. The 200 larvae examined, 15 per generation, did not present spines in the column of the ventral process of the penultimate abdominal segment and the column of the ventral process was triangular and the apex of the column process presented numerous spines. These characteristics allowed identifying these specimens as C. albiceps. However, since C. albiceps has the ability to damage intact tissues, it may be causing relevant aggravation when associated with C. hominivorax and can not be considered innocuous